octagon FV-1

[oip]

hello

just finished another build from pedalPCB - i've tried messing around with the FV-1 before including on breadboard but this is the first time i've made a proper build with it.  great pedal!  the included reverbs are very nice.  having 8 possible effects in the one box is pretty amazing.

also first time trying tamiya model paint underneath, and a full face laser waterslide decal wrapping around the top of the box.  it was fun, the paint is intense.  too impatient to get it perfect, the decal broke in a couple of spots, but it seems pretty durable under the clear coat.

next step is buying some EEPROMs, copying some more existing programs and trying to program my own.  i love the OBNE dark star so i'm going to try and copy that (possibly by.. just copying the EEPROM)





with its buddy

[matmosphere]

Nice! Clean builds and Love the artwork.

[junkemail86]

Nice!
Anybody know about the pedalPCB Module 8?  I'm considering the Octagon vs Module 8.
How do you like the Octagon?  Seems like an awesome project

[sonnyboy27]

Nice!
Anybody know about the pedalPCB Module 8?  I'm considering the Octagon vs Module 8.
How do you like the Octagon?  Seems like an awesome project

I believe the Module 8 is focused on modulation effects and the Octagon has a variety of modulation, reverb, and delay.

[oip]

thanks guys!

Anybody know about the pedalPCB Module 8?  I'm considering the Octagon vs Module 8.
How do you like the Octagon?  Seems like an awesome project

just looking at it now they appear to be the same board, but different programs on the EEPROM.  so it depends whether you prefer modulation or reverb/delay.  the EEPROM is socketed so if you get a pickit or similar programmer you can always put both types of effects on there (that's what i'm going to be doing).

as a standalone the octagon is great though, a lot of variety in the effects.  expression pedal mod is on another thread here and having played around with the effects, it would be worth it.

[Boba7]

That looks so cool! Love the wiring too

[Scottosan]

How is the mix working out for you.  I haven't done the octagon but have don the DMD-2.  I found that with the mix at 12:00, the dry signal was lower than unity gain.  The signal is stronger coming from the FV-1 than from the first op amp.  I used a 150k resistor across legs 1 and 2 of the mix control to allow more clean signal pass and leave the FV-1 signal untouched.  I found this much more balanced.  I may drop the 150k just a tad, more, but to me this was much improved on balancing the levels

[p_wats]

Those are hand-painted? They look great! I've done some acrylic painting on enclosures before with some success, but mostly just end up doing abstract spray painting/splatter.

[oip]

thanks!

How is the mix working out for you.  I haven't done the octagon but have don the DMD-2.  I found that with the mix at 12:00, the dry signal was lower than unity gain.  The signal is stronger coming from the FV-1 than from the first op amp.  I used a 150k resistor across legs 1 and 2 of the mix control to allow more clean signal pass and leave the FV-1 signal untouched.  I found this much more balanced.  I may drop the 150k just a tad, more, but to me this was much improved on balancing the levels

interesting, i haven't really tried to fine tune the mix but it wouldn't surprise me if noon isn't unity gain.  i've been adjusting with the volume to suit depending on the patch and settings, it's definitely nice to have an overall volume control.

Those are hand-painted? They look great! I've done some acrylic painting on enclosures before with some success, but mostly just end up doing abstract spray painting/splatter.

aha i wish! they are art by stacey rozich, i used waterslide decal for this one and paper for the BE-OD. i would love to try hand painting acrylic like the zvex originals but have very limited skills (ie: no skills) so haven't wanted to buy a paint set.

[Aleph Null]

These builds look great. The graphic design is spectacular. Even if you didn't do the illustrations, the lettering and knob choice is perfect. You've definitely inspired me to dig through children's books for pedal artwork.

[oip]

thanks so much!  i have a love/hate relationship with pedal artwork, it's so fiddly and always a bottleneck in finishing builds.  still trying different methods. 

currently waiting on signup for the spinCAD forums to start programming some eeproms

[sonnyboy27]

How is the mix working out for you.  I haven't done the octagon but have don the DMD-2.  I found that with the mix at 12:00, the dry signal was lower than unity gain.  The signal is stronger coming from the FV-1 than from the first op amp.  I used a 150k resistor across legs 1 and 2 of the mix control to allow more clean signal pass and leave the FV-1 signal untouched.  I found this much more balanced.  I may drop the 150k just a tad, more, but to me this was much improved on balancing the levels

Do you get unity gain somewhere roughly around noon though? It could be pot tolerance. I'm getting ready to build the Octagon so I'm curious.

[oip]

hmm lemme check when i get home.  as i said, been leaning on the volume pot mostly and dialling it in by feel.  i *think* that with both volume and mix at noon it will be close to unity but wouldn't be surprised if the wet signal is louder than the dry. 

[Scottosan]

How is the mix working out for you.  I haven't done the octagon but have don the DMD-2.  I found that with the mix at 12:00, the dry signal was lower than unity gain.  The signal is stronger coming from the FV-1 than from the first op amp.  I used a 150k resistor across legs 1 and 2 of the mix control to allow more clean signal pass and leave the FV-1 signal untouched.  I found this much more balanced.  I may drop the 150k just a tad, more, but to me this was much improved on balancing the levels

Do you get unity gain somewhere roughly around noon though? It could be pot tolerance. I'm getting ready to build the Octagon so I'm curious.

my mix pot measured at 96.7k. Keep in mind my comment is around the DMD2 although the topologies are similar. I get unity on my dry at 10:00 which doesn’t allow for much effect signal as the FV-1 signal is at 70k resistance at this point. That may be fine for some obscure algorithms but for most time based effects, the clean signal should be unity throughout the sweep and mix shoul introduce or remove effect signal. I cannot speak to the octagon but looking at the schematic it likely suffers from the same design flaw. Probably a fun pedal but not ideal for  serious studio or gigging use. I have since redesigned the mix so that clean is unity throughout and effect level is mixed in.  I think a generic topology is used for these boards but not ideal for all algorithms without  treaking.  I did the hypernova Reverb as well a it is honestly a noise pedal. Clean is processed through the FV-1 instead of mixed. The second half of the IC is configured for 6db gain boost only to have to turn down the 100kb volume to get unity. This adds unnecessary non-linear noise. I redid it for unity gain which significantly removed unessasarry noise but the noise floor is still evident especially with clean guitar signal. It can easily hide behind the noise floor of a stomp box ahead of it but overall both builds have left me underwhelmed. I feel like a vanilla dev board type schematic was used for these with no effort to optimize for the given effects

[oip]

the analogs around the FV-1 in all the DIY builds i've seen, as well as numerous commercial pedals, are definitely generic.  i don't know enough about circuit design to improve them, but i'm interested in builds like catalinbread echorec using more specific preamp structures, and eventually have some goal of combining the SDD3000 preamp (as in the aion eclipse) and an FV-1 circuit.